Faculty

Walter Eckhart

Education

BS, Biophysics, Yale University

Postgraduate research, University of Cambridge, England

PhD, Molecular Biology, University of California, Berkeley

Postdoctoral fellow, The Salk Institute

Research

Walter Eckhart served as director of the Salk Institute Cancer Center and head of the Molecular and Cell Biology Laboratory for more than 30 years. He studied regulation of cell growth, including the effects of cancer-causing genes (oncogenes), growth factors, and communication between adjacent cells (gap junctional intercellular communication). Currently professor emeritus at the Salk Institute, he is a member of advisory committees for cancer centers, the National Institutes of Health, and voluntary health agencies.

"The overall interest of my laboratory has been the regulation of cell growth,
including the action of cancer-causing genes, communication between cells,
and the effects of growth factors on the development of breast cancer."

The growth of cells is tightly controlled, but
cancer cells turn a deaf ear to signals that
cause normal cells to stop dividing. Eckhart
identified and characterized genes in tumor
viruses—so-called viral oncogenes—that
override normal cell cycle controls. The
viral genes he studied stimulate cellular
growth signaling pathways, allowing the
cells to divide continuously. Identification
of growth signaling pathways has led to
the development of drugs that inhibit the
growth of cancer cells.

Cancer cells also lose the ability to communicate
with each other through the
exchange of materials through channels
called gap junctions. This communication
is important for coordinating the activities
of cells in tissues, including normal regulation
of cell growth. The proteins that
form the channels are called connexins.
Eckhart found that some cancer-causing
genes modify connexins, thereby shutting
off communication between adjacent cells
and disrupting normal growth. Restoration
of communication allows the cells to grow
normally again, suggesting that agents that
regulate cellular communication might help
in reversing cancer. Eckhart also studied
the effects of a growth factor, insulin-like
growth factor-1 (IGF-1), on human mammary
epithelial cells growing in a threedimensional
culture system that mimics
the environment of the body. Abnormal
signaling by IGF-1 stimulated changes in
the growth properties of the cells, similar
to changes that happen during early tumor
development. Studies like these are helping
to define how changes in genes and growth
signaling can lead to breast cancer.

Eckhart served as director of the Salk
Institute Cancer Center and head of the
Molecular and Cell Biology Laboratory for
more than 30 years. He phased out his
laboratory research program and became
professor emeritus in 2010. He presently
serves on advisory committees for cancer
centers, the National Institutes of Health
and voluntary health agencies.

Selected Publications

Olbina, G. and Eckhart, W. (2003). Mutations in the second extra-cellular region of connexin 43 prevent localization to the plasma membrane, but do not affect its ability to suppress cell growth. Mol. Cancer Res. 1:690-700.

Hunter, T. and Eckhart, W. (2004). The discovery of tyrosine phosphorylation: it's all in the buffer! Cell S116:S35-S39.